This invention relates to absorption air conditioning, and, in particular, to a refrigerant management system for use in an absorption heating and cooling machine.
As is well known, in an absorption heating and cooling system, a refrigerant is initially brought together with an absorbent capable of holding a high concentration of refrigerant to produce a solution suitable for use in the process. Under certain operating conditions, the amount of refrigerant necessary to keep the system running efficiently may vary. Typically, a sufficient amount of refrigerant is stored in the machine so that it is available to meet the demands during these peak operation periods. Allowing the amount of available refrigerant to become depleted will cause the refrigerant pump to cavitate or produce crystallization of the absorbent.
Although it is possible to store excessive amounts of refrigerant in an absorption machine to meet peak load demands, this practice is not only space consuming, but also economically impractical.
In an unexamined Japanese application assigned to Ebara Ltd. of Tokyo, Japan (62-178858) there is disclosed an absorption machine in which the gravity flow of liquid refrigerant between the system condenser and the system evaporator is controlled in response to certain sensed system related conditions, such as, the solution temperature as it is leaving the absorber. A reservoir for liquid refrigerant is provided inside the condenser and the refrigerant is metered to the evaporator through a first flow path under normal operating conditions. Upon the sensing of an operational condition that demands more than normal amounts of refrigerant, a second flow path in the reservoir is opened which draws the condenser reservoir to the evaporator. Although this system solves some of the problems associated with refrigerant management in an absorption machine, it nevertheless requires a relatively large refrigerant storage area in the condenser unit. Because the reservoir is confined to the evaporator, it provides little flexibility in relocating the reservoir into more practical and convenient machine locations.